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ASTRONOMY AND ASTROPHYSICS 1 H 0419-577 : a “ two-state ” soft X-ray Seyfert galaxy ?
| Content Provider | Semantic Scholar |
|---|---|
| Author | Guainazzi, Matteo Comastri, Andrea Stirpe, Giovanna Maria Brandt, William Nielsen Fiore, Fabrizio Leighly, Karen Marie Matt, Giorgio Molendi, Silvano Puchnarewicz, Elizabeth Piro, Luigi Siemiginowska, Aneta |
| Copyright Year | 1998 |
| Abstract | In this paper we report on the first simultaneous optical and X-ray (Beppo-SAX) observations of the radio-quiet AGN 1H0419-577. The optical spectrum clearly leads us to classify this source as a Seyfert 1. The X-ray spectrum is, however, somewhat at odds with this classification: a simple flat (Γ ∼ 1.55) and featureless power-law is a good description of the whole 1.8-40 keV spectrum, even if the upper limit to a broad iron line is not very tight. An analysis of a still unpublished ROSAT observation of the same target reveals that the soft X-ray spectrum has undergone a transition from a steep (Γ = 2.5) to a flat (Γ = 1.55) state, at least in the 0.7-2 keV band. If this difference is due to a remarkably variable soft excess, it is unlikely that a single component is responsible for the optical/UV/soft X-ray spectral distribution. The hypothesis that the difference is due to a change in the primary X-ray continuum and its implications for current Comptonization models are discussed. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://aa.springer.de/papers/8339002/2300327.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
